public class Test {
    public static void main(String[] args) {
    }

    public static ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode newhead = null;
        ListNode cur = newhead;
        int tmp = 0;
        while (l1 != null || l2 != null) {
            int n1 = l1 != null ? l1.val : 0;
            int n2 = l2 != null ? l2.val : 0;
            int sum = n1 + n2 + tmp;
            if (newhead == null) {
                newhead = cur = new ListNode(sum % 10);
            } else {
                cur.next = new ListNode(sum % 10);
                cur = cur.next;
            }
            tmp = sum / 10;
            if (l1 != null) {
                l1 = l1.next;
            }
            if (l2 != null) {
                l2 = l2.next;
            }
            if (tmp != 0) {
                cur.next = new ListNode(tmp);
            }
        }
        return newhead;
    }
}

class ListNode {
    int val;
    ListNode next;

    ListNode() {
    }

    ListNode(int val) {
        this.val = val;
    }

    ListNode(int val, ListNode next) {
        this.val = val;
        this.next = next;
    }
}
